Relational databases include one or more tables, organized by columns and rows, in which the table includes data of an entity type, columns of the table represent a particular attribute of the entity type, and rows include records of the attributes for the entity type. The preponderance of focus on database applications and engines addresses improvement of performance of returning results of queries. To improve the performance of response to data queries, databases may create an index of a table, based on at least one data column of the table, and includes a memory location reference to the table row associated with the content of a particular indexed column entry. An index often uses a sorted binary tree to organize the column data, enabling a faster search in response to some queries, avoiding a search through all the entries of one or more database tables.
In some cases, database management applications dynamically modify indexes according to conditions associated with database queries; however, these activities are also associated with optimizations to improve query response performance. For example, in some situations, it is uncommon for resource requirements to be equally considered in optimization of database queries, as the focus of most optimizations are on the time performance of providing results to queries.